/Engine/Plugins/Online/OnlineFramework/Source/Party/Public/SocialToolkit.h
Handle result of AcceptFriendInvite
void HandleAcceptFriendInviteComplete ( int32 LocalUserNum, bool bWasSuccessful, const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & InviterUserId, const [FString](API\Runtime\Core\Containers\FString) & ListName, const [FString](API\Runtime\Core\Containers\FString) & ErrorStr )